1. Field of the Invention
The present invention relates generally to a gas switch, and more particularly to a gas switch that is capable of achieving smooth adjustment of fire in different intensity from strong fire to weak fire.
2. Description of the Related Art
Conventionally, the method used in a gas switch to adjust fire intensity is often achieved by using a drive rotating shaft to drive a fastener inside the switch body to rotate, so as to make air ports or guide slots in different diameter on the fastener correspond with air intake holes inside the switch body respectively. In such a way, the gas switch will generate different fire intensity as the drive rotating shaft revolves to release gas of different flows. Since usually there is space between the air ports or guide slots in different diameter, the cross section area for gas flows will not be evenly altered in the process of adjusting different air ports or guide slots to correspond with the air intake. As a result, it is impossible to achieve smooth and linear changes in the course of adjusting fire among different intensities, thus further making it impossible for users to finely adjust the fire intensity of gas stoves effectively.
To solve this problem, someone designed a kind of gas switches able to adjust fire intensity. On the fastener of such gas switch, only one guide slot and gas guide hole is installed and connected with the internal through hole, and the guide slot is joint with the gas intake hole. So, the slide guide component built on the drive shaft rod can work with the undulant guide to make the drive rotating shaft generate axial displacement as the shaft rotates, thus changing the space between one end of the fastener rod and the air outlet hole and further adjusting the cross-section area for gas flows. By doing so, it will achieve relatively smooth changes among fires of high, medium and low intensities.
While the aforesaid design of gas switches can lead to smooth changes of fire in different intensity, its slide guide component in the shape of a round rod can be built into the slot at one end of the fastener, in addition to working with the guide. Therefore, the drive rotating shaft can drive the fastener to rotate as it revolves. In another word, the slide guide component serves not only as a structure to control axial displacement of the drive shaft rod, but also as a component to rotate the fastener. However, the slide guide component is liable to wear and tear due to friction with walls of the fastener slot in the long period and effect of payloads generated in driving the fastener to rotate since it is a tiny component in the shape of a round rod. Moreover, in the cases where the slide guide component is worn out, control error will occur in the process of working with the guide to make the drive shaft rod generate axial displacement, which, in return, will lead to the result that fires in different intensities cannot be smoothly changed in a real way. Therefore, it is obvious that such gas switches still have defects in practical applications.